The present invention relates to a guide tube and, more particularly, to a guide tube to guide an endoscope or a therapeutic device into a body.
Hitherto, two methods have been generally used for a diagnosis and/or a therapeutic treatment using an endoscope. According to the first method, an endoscope is inserted through a bodily orifice, such as the mouth, anus, or urethra, to diagnose or therapeutically treat the alimentary canal, a digestive organ, or urinary organ. According to the second method, a perforation is formed in an abdominal wall on the outside of a body cavity and an endoscope is inserted through the perforation to conduct a diagnosis and a therapeutic treatment of an organ through an abdominal cavity. In the first method, since a perforation is not needed, the burden on the patient is small. However, since the therapeutic treatment is performed through a narrow tubular cavity, only a portion in the tubular cavity can be treated. In the second method, the perforation is formed in the abdominal wall and an endoscope and one or more surgical instruments are inserted through the perforation to perform therapeutic treatment. Various therapeutic treatments can be performed. However, since a perforation is formed in the abdominal wall, it takes time for the perforation to heal.
U.S. Pat. No. 5,297,536 discloses the following manipulation. According to the manipulation, a tube is inserted into the stomach through the mouth. A perforation is formed in the stomach wall by an incising instrument inserted through the tube. An endoscope is then inserted into the abdominal cavity through the perforation. A therapeutic treatment is then performed in the abdominal cavity using the endoscope. Finally, the perforation is closed.
As mentioned above, when the endoscope is inserted into the abdominal cavity through the stomach wall, it is preferable that a distal end of a guide tube guiding the endoscope be fixed to the stomach wall. This is because, if the distal end of the guide tube is dropped in the stomach, the endoscope cannot be inserted stably.
The conventional guide tube to insert the endoscope into the stomach through the mouth is intended to easily pass the endoscope through the pharynx. Accordingly, the length of the conventional guide tube is about 200 to 300 mm. On the other hand, the distance from the mouth to the pharynx is about 100 mm, the length of the esophagus is about 250 mm, and the distance from a cardia to a pylorus of the stomach is 200 to 250 mm. Accordingly, in order to guide the endoscope to the stomach wall through the mouth, a guide tube of 550 mm or longer is needed. Therefore, conventional guide tubes cannot reach the stomach wall. U.S. Pat. No. 5,297,536 does not disclose fixing the guide tube to the stomach wall.
On the other hand, European Patent No. 1,025,802 discloses a guide tube which is percutaneously inserted into the small intestine through the abdominal wall. Many methods for percutaneously fixing the guide tube to the abdominal wall have been disclosed. For example, in Jpn. Pat. Appln. KOKAI Publication No. 6-54798, an abdominal wall is sandwiched between two balloons to fix a tube to the abdominal wall. The size of each balloon is also disclosed. The balloons are effectively used for fixing the tube to the abdominal wall. However, the anatomical thickness of the stomach wall is 3 to 8 mm. Accordingly, the conventional balloons are not of an appropriate size for fixing the tube to the stomach wall, because the tube cannot be securely fixed.
Furthermore, after diagnosis or therapeutic treatment of the abdominal cavity are finished through the stomach wall, it is necessary to close the perforation in the stomach wall. The foregoing U.S. Pat. No. 5,297,536 discloses the following device. According to the device, a tube and a rubber ring are attached to the periphery of the endoscope and the perforation is closed using the rubber ring. When the closing device is used, tissue around the perforation is withdrawn into the tube, drawn into the device and ligatured by the ring. However, it is difficult to draw the area surrounding the perforation in the stomach wall into the tube, therefore the closing operation may sometimes not be performed satisfactorily.